Process for making contained layers and devices made with same

ABSTRACT

There is provided a process for forming a contained second layer over a first layer, including the steps:
         forming the first layer having a first surface energy;   treating the first layer with a reactive surface-active composition to form a treated first layer having a second surface energy which is lower than the first surface energy;   exposing the treated first layer with radiation; and   forming the second layer.
 
There is also provided an organic electronic device made by the process.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation-in-Part of U.S. Ser. No. 11/401,151,filed Apr. 10, 2006, which claims priority to provisional applicationSer. No. 60/751,549, dated Mar. 2, 2006.

BACKGROUND INFORMATION

1. Field of the Disclosure

This disclosure relates in general to a process for making an electronicdevice. It further relates to the device made by the process.

2. Description of the Related Art

Electronic devices utilizing organic active materials are present inmany different kinds of electronic equipment. In such devices, anorganic active layer is sandwiched between two electrodes.

One type of electronic device is an organic light emitting diode (OLED).OLEDs are promising for display applications due to their highpower-conversion efficiency and low processing costs. Such displays areespecially promising for battery-powered, portable electronic devices,including cell-phones, personal digital assistants, handheld personalcomputers, and DVD players. These applications call for displays withhigh information content, full color, and fast video rate response timein addition to low power consumption.

Current research in the production of full-color OLEDs is directedtoward the development of cost effective, high throughput processes forproducing color pixels. For the manufacture of monochromatic displays byliquid processing, spin-coating processes have been widely adopted (see,e.g., David Braun and Alan J. Heeger, Appl. Phys. Letters 58, 1982(1991)). However, manufacture of full-color displays requires certainmodifications to procedures used in manufacture of monochromaticdisplays. For example, to make a display with full-color images, eachdisplay pixel is divided into three subpixels, each emitting one of thethree primary display colors, red, green, and blue. This division offull-color pixels into three subpixels has resulted in a need to modifycurrent processes to prevent the spreading of the liquid coloredmaterials (i.e., inks) and color mixing.

Several methods for providing ink containment are described in theliterature. These are based on containment structures, surface tensiondiscontinuities, and combinations of both. Containment structures aregeometric obstacles to spreading: pixel wells, banks, etc. In order tobe effective these structures must be large, comparable to the wetthickness of the deposited materials. When the emissive ink is printedinto these structures it wets onto the structure surface, so thicknessuniformity is reduced near the structure. Therefore the structure mustbe moved outside the emissive “pixel” region so the non-uniformities arenot visible in operation. Due to limited space on the display(especially high-resolution displays) this reduces the availableemissive area of the pixel. Practical containment structures generallyhave a negative impact on quality when depositing continuous layers ofthe charge injection and transport layers. Consequently, all the layersmust be printed.

In addition, surface tension discontinuities are obtained when there areeither printed or vapor deposited regions of low surface tensionmaterials. These low surface tension materials generally must be appliedbefore printing or coating the first organic active layer in the pixelarea. Generally the use of these treatments impacts the quality whencoating continuous non-emissive layers, so all the layers must beprinted.

An example of a combination of two ink containment techniques isCF₄-plasma treatment of photoresist bank structures (pixel wells,channels). Generally, all of the active layers must be printed in thepixel areas.

All these containment methods have the drawback of precluding continuouscoating. Continuous coating of one or more layers is desirable as it canresult in higher yields and lower equipment cost. There exists,therefore, a need for improved processes for forming electronic devices.

SUMMARY

There is provided a process for forming a contained second layer over afirst layer, said process comprising:

-   -   forming the first layer having a first surface energy;    -   treating the first layer with a reactive surface-active        composition to form a treated first layer having a second        surface energy which is lower than the first surface energy;    -   exposing the treated first layer with radiation; and    -   forming the second layer.

There is provided a process for making an organic electronic devicecomprising a first organic active layer and a second organic activelayer positioned over an electrode, said process comprising:

-   -   forming the first organic active layer having a first surface        energy over the electrode;    -   treating the first organic active layer with a reactive        surface-active composition to form a treated first organic        active layer having a second surface energy which is lower than        the first surface energy;    -   exposing the treated first organic active layer with radiation;        and    -   forming the second organic active layer.

There is also provided an organic electronic device comprising a firstorganic active layer and a second organic active layer positioned overan electrode, and further comprising a reactive surface-activecomposition between the first organic active layer and the secondorganic active layer.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated in the accompanying figures to improveunderstanding of concepts as presented herein.

FIG. 1 includes a diagram illustrating contact angle.

FIG. 2 includes an illustration of an organic electronic device.

FIG. 3 includes an illustration of a substrate with anode lines.

FIG. 4 includes an illustration of the substrate of FIG. 3 coated with abuffer material.

FIG. 5 includes an illustration of the substrate of FIG. 4 furthercoated with a reactive surface-active composition.

FIG. 6 includes an illustration of the substrate of FIG. 5 afterexposure and development.

Skilled artisans appreciate that objects in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the objects in the figures may beexaggerated relative to other objects to help to improve understandingof embodiments.

DETAILED DESCRIPTION

There is provided a process for forming a contained second layer over afirst layer, said process comprising:

-   -   forming the first layer having a first surface energy;    -   treating the first layer with a reactive surface-active        composition to form a treated first layer having a second        surface energy which is lower than the first surface energy;    -   exposing the treated first layer with radiation; and    -   applying the second layer over the treated and exposed first        layer.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and benefits of any one or more of the embodiments willbe apparent from the following detailed description, and from theclaims. The detailed description first addresses Definitions andClarification of Terms followed by the Reactive Surface-activecomposition, the Process, the Organic Electronic Device, and finallyExamples.

1. Definitions and Clarification of Terms

Before addressing details of embodiments described below, some terms aredefined or clarified.

The term “active” when referring to a layer or material, is intended tomean a layer or material that exhibits electronic or electro-radiativeproperties. In an electronic device, an active material electronicallyfacilitates the operation of the device. Examples of active materialsinclude, but are not limited to, materials which conduct, inject,transport, or block a charge, where the charge can be either an electronor a hole, and materials which emit radiation or exhibit a change inconcentration of electron-hole pairs when receiving radiation. Examplesof inactive materials include, but are not limited to, planarizationmaterials, insulating materials, and environmental barrier materials.

The term “contained” when referring to a layer, is intended to mean thatthe layer does not spread significantly beyond the area where it isdeposited. The layer can be contained by surface energy affects or acombination of surface energy affects and physical barrier structures.

The term “electrode” is intended to mean a member or structureconfigured to transport carriers within an electronic component. Forexample, an electrode may be an anode, a cathode, a capacitor electrode,a gate electrode, etc. An electrode may include a part of a transistor,a capacitor, a resistor, an inductor, a diode, an electronic component,a power supply, or any combination thereof.

The term “organic electronic device” is intended to mean a deviceincluding one or more organic semiconductor layers or materials. Anorganic electronic device includes, but is not limited to: (1) a devicethat converts electrical energy into radiation (e.g., a light-emittingdiode, light emitting diode display, diode laser, or lighting panel),(2) a device that detects a signal using an electronic process (e.g., aphotodetector, a photoconductive cell, a photoresistor, a photoswitch, aphototransistor, a phototube, an infrared (“IR”) detector, or abiosensors), (3) a device that converts radiation into electrical energy(e.g., a photovoltaic device or solar cell), (4) a device that includesone or more electronic components that include one or more organicsemiconductor layers (e.g., a transistor or diode), or any combinationof devices in items (1) through (4).

The term “fluorinated” when referring to an organic compound, isintended to mean that one or more of the hydrogen atoms in the compoundhave been replaced by fluorine. The term encompasses partially and fullyfluorinated materials.

The term(s) “radiating/radiation” means adding energy in any form,including heat in any form, the entire electromagnetic spectrum, orsubatomic particles, regardless of whether such radiation is in the formof rays, waves, or particles.

The term “reactive surface-active composition” is intended to mean acomposition that comprises at least one material which is radiationsensitive, and when the composition is applied to a layer, the surfaceenergy of that layer is reduced. Exposure of the reactive surface-activecomposition to radiation results in the change in at least one physicalproperty of the composition. The term is abbreviated “RSA”, and refersto the composition both before and after exposure to radiation.

The term “radiation sensitive” when referring to a material, is intendedto mean that exposure to radiation results in at least one chemical,physical, or electrical property of the material.

The term “surface energy” is the energy required to create a unit areaof a surface from a material. A characteristic of surface energy is thatliquid materials with a given surface energy will not wet surfaces witha lower surface energy.

The term “layer” is used interchangeably with the term “film” and refersto a coating covering a desired area. The term is not limited by size.The area can be as large as an entire device or as small as a specificfunctional area such as the actual visual display, or as small as asingle sub-pixel. Layers and films can be formed by any conventionaldeposition technique, including vapor deposition, liquid deposition(continuous and discontinuous techniques), and thermal transfer.

The term “liquid composition” is intended to mean a liquid medium inwhich a material is dissolved to form a solution, a liquid medium inwhich a material is dispersed to form a dispersion, or a liquid mediumin which a material is suspended to form a suspension or an emulsion.“Liquid medium” is intended to mean a material that is liquid withoutthe addition of a solvent or carrier fluid, i.e., a material at atemperature above its solidification temperature.

The term “liquid containment structure” is intended to mean a structurewithin or on a workpiece, wherein such one or more structures, by itselfor collectively, serve a principal function of constraining or guiding aliquid within an area or region as it flows over the workpiece. A liquidcontainment structure can include cathode separators or a wellstructure.

The term “liquid medium” is intended to mean a liquid material,including a pure liquid, a combination of liquids, a solution, adispersion, a suspension, and an emulsion. Liquid medium is usedregardless whether one or more solvents are present.

As used herein, the term “over” does not necessarily mean that a layer,member, or structure is immediately next to or in contact with anotherlayer, member, or structure. There may be additional, interveninglayers, members or structures.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Also, use of “a” or “an” are employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural unless it is obvious that it is meant otherwise.

Group numbers corresponding to columns within the Periodic Table of theelements use the “New Notation” convention as seen in the CRC Handbookof Chemistry and Physics, 81^(st) Edition (2000-2001).

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of embodiments of the present invention, suitablemethods and materials are described below. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety, unless a particular passageis cited. In case of conflict, the present specification, includingdefinitions, will control. In addition, the materials, methods, andexamples are illustrative only and not intended to be limiting.

To the extent not described herein, many details regarding specificmaterials, processing acts, and circuits are conventional and may befound in textbooks and other sources within the organic light-emittingdiode display, photodetector, photovoltaic, and semiconductive memberarts.

2. Reactive Surface-Active Composition

The reactive surface-active composition (“RSA”) is a radiation-sensitivecomposition. When exposed to radiation, at least one physical propertyand/or chemical property of the RSA is changed such that the exposed andunexposed areas can be physically differentiated. Treatment with the RSAlowers the surface energy of the material being treated.

In one embodiment, the RSA is a radiation-hardenable composition. Inthis case, when exposed to radiation, the RSA can become more soluble ordispersable in a liquid medium, less tacky, less soft, less flowable,less liftable, or less absorbable. Other physical properties may also beaffected.

In one embodiment, the RSA is a radiation-softenable composition. Inthis case, when exposed to radiation, the RSA can become less soluble ordispersable in a liquid medium, more tacky, more soft, more flowable,more liftable, or more absorbable. Other physical properties may also beaffected.

The radiation can be any type of radiation to which results in aphysical change in the RSA. In one embodiment, the radiation is selectedfrom infrared radiation, visible radiation, ultraviolet radiation, andcombinations thereof.

Physical differentiation between areas of the RSA exposed to radiationand areas not exposed to radiation, hereinafter referred to as“development,” can be accomplished by any known technique. Suchtechniques have been used extensively in the photoresist art. Examplesof development techniques include, but are not limited to, treatmentwith a liquid medium, treatment with an absorbant material, treatmentwith a tacky material, and the like.

In one embodiment, the RSA consists essentially of one or moreradiation-sensitive materials. In one embodiment, the RSA consistsessentially of a material which, when exposed to radiation, hardens, orbecomes less soluble, swellable, or dispersible in a liquid medium, orbecomes less tacky or absorbable. In one embodiment, the RSA consistsessentially of a material having radiation polymerizable groups.Examples of such groups include, but are not limited to olefins,acrylates, methacrylates and vinyl ethers. In one embodiment, the RSAmaterial has two or more polymerizable groups which can result incrosslinking. In one embodiment, the RSA consists essentially of amaterial which, when exposed to radiation, softens, or becomes moresoluble, swellable, or dispersible in a liquid medium, or becomes moretacky or absorbable. In one embodiment, the RSA consists essentially ofat least one polymer which undergoes backbone degradation when exposedto deep UV radiation, having a wavelength in the range of 200-300 nm.Examples of polymers undergoing such degradation include, but are notlimited to, polyacrylates, polymethacrylates, polyketones, polysulfones,copolymers thereof, and mixtures thereof.

In one embodiment, the RSA consists essentially of at least one reactivematerial and at least one radiation-sensitive material. Theradiation-sensitive material, when exposed to radiation, generates anactive species that initiates the reaction of the reactive material.Examples of radiation-sensitive materials include, but are not limitedto, those that generate free radicals, acids, or combinations thereof.In one embodiment, the reactive material is polymerizable orcrosslinkable. The material polymerization or crosslinking reaction isinitiated or catalyzed by the active species. The radiation-sensitivematerial is generally present in amounts from 0.001% to 10.0% based onthe total weight of the RSA.

In one embodiment, the RSA consists essentially of a material which,when exposed to radiation, hardens, or becomes less soluble, swellable,or dispersible in a liquid medium, or becomes less tacky or absorbable.In one embodiment, the reactive material is an ethylenically unsaturatedcompound and the radiation-sensitive material generates free radicals.Ethylenically unsaturated compounds include, but are not limited to,acrylates, methacrylates, vinyl compounds, and combinations thereof. Anyof the known classes of radiation-sensitive materials that generate freeradicals can be used. Examples of radiation-sensitive materials whichgenerate free radicals include, but are not limited to, quinones,benzophenones, benzoin ethers, aryl ketones, peroxides, biimidazoles,benzyl dimethyl ketal, hydroxyl alkyl phenyl acetophone, dialkoxyactophenone, trimethylbenzoyl phosphine oxide derivatives, aminoketones,benzoyl cyclohexanol, methyl thio phenyl morpholino ketones, morpholinophenyl amino ketones, alpha halogennoacetophenones, oxysulfonyl ketones,sulfonyl ketones, oxysulfonyl ketones, sulfonyl ketones, benzoyl oximeesters, thioxanthrones, camphorquinones, ketocoumarins, and Michler'sketone. Alternatively, the radiation sensitive material may be a mixtureof compounds, one of which provides the free radicals when caused to doso by a sensitizer activated by radiation. In one embodiment, theradiation sensitive material is sensitive to visible or ultravioletradiation.

In one embodiment, the RSA is a compound having one or morecrosslinkable groups. Crosslinkable groups can have moieties containinga double bond, a triple bond, a precursor capable of in situ formationof a double bond, or a heterocyclic addition polymerizable group. Someexamples of crosslinkable groups include benzocyclobutane, azide,oxiran, di(hydrocarbyl)amino, cyanate ester, hydroxyl, glycidyl ether,C1-10 alkylacrylate, C1-10 alkylmethacrylate, alkenyl, alkenyloxy,alkynyl, maleimide, nadimide, tri(C1-4)alkylsiloxy, tri(C1-4)alkylsilyl,and halogenated derivatives thereof. In one embodiment, thecrosslinkable group is selected from the group consisting ofvinylbenzyl, p-ethenylphenyl, perfluoroethenyl, perfluoroehtenyloxy,benzo-3,4-cyclobutan-1-yl, and p-(benzo-3,4-cyclobutan-1-yl)phenyl.

In one embodiment, the reactive material can undergo polymerizationinitiated by acid, and the radiation-sensitive material generates acid.Examples of such reactive materials include, but are not limited to,epoxies. Examples of radiation-sensitive materials which generate acid,include, but are not limited to, sulfonium and iodonium salts, such asdiphenyliodonium hexafluorophosphate.

In one embodiment, the RSA consists essentially of a material which,when exposed to radiation, softens, or becomes more soluble, swellable,or dispersible in a liquid medium, or becomes more tacky or absorbable.In one embodiment, the reactive material is a phenolic resin and theradiation-sensitive material is a diazonaphthoquinone.

Other radiation-sensitive systems that are known in the art can be usedas well.

In one embodiment, the RSA comprises a fluorinated material. In oneembodiment, the RSA comprises an unsaturated material having one or morefluoroalkyl groups. In one embodiment, the fluoroalkyl groups have from2-20 carbon atoms. In one embodiment, the RSA is a fluorinated acrylate,a fluorinated ester, or a fluorinated olefin monomer. Examples ofcommercially available materials which can be used as RSA materials,include, but are not limited to, Zonyl® 8857A, a fluorinated unsaturatedester monomer available from E. I. du Pont de Nemours and Company(Wilmington, Del.), and3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-eneicosafluorododecylacrylate (H₂C═CHCO₂CH₂CH₂(CF₂)₉CF₃) available from Sigma-Aldrich Co.(St. Louis, Mo.).

In one embodiment, the RSA is a fluorinated macromonomer. As usedherein, the term “macromonomer” refers to an oligomeric material havingone or more reactive groups which are terminal or pendant from thechain. In some embodiments, the macromonomer has a molecular weightgreater than 1000; in some embodiments, greater than 2000; in someembodiments, greater than 5000. In some embodiments, the backbone of themacromonomer includes ether segments and perfluoroether segments. Insome embodiments, the backbone of the macromonomer includes alkylsegments and perfluoroalkyl segments. In some embodiments, the backboneof the macromonomer includes partially fluorinated alkyl or partiallyfluorinated ether segments. In some embodiments, the macromonomer hasone or two terminal polymerizable or crosslinkable groups.

In one embodiment, the RSA is an oligomeric or polymeric material havingcleavable side chains, where the material with the side chains formsfilms with a different surface energy that the material without the sidechains. In one embodiment, the RSA has a non-fluorinated backbone andpartially fluorinated or fully fluorinated side chains. The RSA with theside chains will form films with a lower surface energy than films madefrom the RSA without the side chains. Thus, the RSA can be can beapplied to a first layer, exposed to radiation in a pattern to cleavethe side chains, and developed to remove the side chains. This resultsin a pattern of higher surface energy in the areas exposed to radiationwhere the side chains have been removed, and lower surface energy in theunexposed areas where the side chains remain. In some embodiments, theside chains are thermally fugitive and are cleaved by heating, as withan infrared laser. In this case, development may be coincidental withexposure in infrared radiation. Alternatively, development may beaccomplished by the application of a vacuum or treatment with solvent.In some embodiment, the side chains are cleavable by exposure to UVradiation. As with the infrared system above, development may becoincidental with exposure to radiation, or accomplished by theapplication of a vacuum or treatment with solvent.

In one embodiment, the RSA comprises a material having a reactive groupand second-type functional group. The second-type functional groups canbe present to modify the physical processing properties or thephotophysical properties of the RSA. Examples of groups which modify theprocessing properties include plasticizing groups, such as alkyleneoxide groups. Examples of groups which modify the photophysicalproperties include charge transport groups, such as carbazole,triarylamino, or oxadiazole groups.

In one embodiment, the RSA reacts with the underlying area when exposedto radiation. The exact mechanism of this reaction will depend on thematerials used. After exposure to radiation, the RSA is removed in theunexposed areas by a suitable development treatment. In someembodiments, the RSA is removed only in the unexposed areas. In someembodiments, the RSA is partially removed in the exposed areas as well,leaving a thinner layer in those areas. In some embodiments, the RSAthat remains in the exposed areas is less than 50 Å in thickness. Insome embodiments, the RSA that remains in the exposed areas isessentially a monolayer in thickness.

3. Process

In the process provided herein, a first layer is formed, the first layeris treated with a reactive surface-active composition (“RSA”), thetreated first layer is exposed to radiation, and a second layer isformed over the treated and exposed first layer.

In one embodiment, the first layer is a substrate. The substrate can beinorganic or organic. Examples of substrates include, but are notlimited to glasses, ceramics, and polymeric films, such as polyester andpolyimide films.

In one embodiment, the first layer is an electrode. The electrode can beunpatterned, or patterned. In one embodiment, the electrode is patternedin parallel lines. The electrode can be on a substrate.

In one embodiment, the first layer is deposited on a substrate. Thefirst layer can be patterned or unpatterned. In one embodiment, thefirst layer is an organic active layer in an electronic device.

The first layer can be formed by any deposition technique, includingvapor deposition techniques, liquid deposition techniques, and thermaltransfer techniques. In one embodiment, the first layer is deposited bya liquid deposition technique, followed by drying. In this case, a firstmaterial is dissolved or dispersed in a liquid medium. The liquiddeposition method may be continuous or discontinuous. Continuous liquiddeposition techniques, include but are not limited to, spin coating,roll coating, curtain coating, dip coating, slot-die coating, spraycoating, and continuous nozzle coating. Discontinuous liquid depositiontechniques include, but are not limited to, ink jet printing, gravureprinting, flexographic printing and screen printing. In one embodiment,the first layer is deposited by a continuous liquid depositiontechnique. The drying step can take place at room temperature or atelevated temperatures, so long as the first material and any underlyingmaterials are not damaged.

The first layer is treated with an RSA. The treatment can becoincidental with or subsequent to the formation of the first layer.

In one embodiment, the RSA treatment is coincidental with the formationof the first organic active layer. In one embodiment, the RSA is addedto the liquid composition used to form the first layer. When thedeposited composition is dried to form a film, the RSA migrates to theair interface, i.e., the top surface, of the first layer in order toreduce the surface energy of the system.

In one embodiment, the RSA treatment is subsequent to the formation ofthe first layer. In one embodiment, the RSA is applied as a separatelayer overlying, and in direct contact with, the first layer.

In one embodiment, the RSA is applied without adding it to a solvent. Inone embodiment, the RSA is applied by vapor deposition. In oneembodiment, the RSA is a liquid at room temperature and is applied byliquid deposition over the first layer. The liquid RSA may befilm-forming or it may be absorbed or adsorbed onto the surface of thefirst layer. In one embodiment, the liquid RSA is cooled to atemperature below its melting point in order to form a second layer overthe first layer. In one embodiment, the RSA is not a liquid at roomtemperature and is heated to a temperature above its melting point,deposited on the first layer, and cooled to room temperature to form asecond layer over the first layer. For the liquid deposition, any of themethods described above may be used.

In one embodiment, the RSA is deposited from a second liquidcomposition. The liquid deposition method can be continuous ordiscontinuous, as described above. In one embodiment, the RSA liquidcomposition is deposited using a continuous liquid deposition method.The choice of liquid medium for depositing the RSA will depend on theexact nature of the RSA material itself. In one embodiment, the RSA is afluorinated material and the liquid medium is a fluorinated liquid.Examples of fluorinated liquids include, but are not limited to,perfluorooctane, trifluorotoluene, and hexafluoroxylene.

In some embodiments, the RSA treatment comprises a first step of forminga sacrificial layer over the first layer, and a second step of applyingan RSA layer over the sacrificial layer. The sacrificial layer is onewhich is more easily removed than the RSA layer by whatever developmenttreatment is selected. Thus, after exposure to radiation, as discussedbelow, the RSA layer and the sacrificial layer are removed in either theexposed or unexposed areas in the development step. The sacrificiallayer is intended to facilitate complete removal of the RSA layer is theselected areas and to protect the underlying first layer from anyadverse affects from the reactive species in the RSA layer.

After the RSA treatment, the treated first layer is exposed toradiation. The type of radiation used will depend upon the sensitivityof the RSA as discussed above. The exposure can be a blanket, overallexposure, or the exposure can be patternwise. As used herein, the term“patternwise” indicates that only selected portions of a material orlayer are exposed. Patternwise exposure can be achieved using any knownimaging technique. In one embodiment, the pattern is achieved byexposing through a mask. In one embodiment, the pattern is achieved byexposing only select portions with a laser. The time of exposure canrange from seconds to minutes, depending upon the specific chemistry ofthe RSA used. When lasers are used, much shorter exposure times are usedfor each individual area, depending upon the power of the laser. Theexposure step can be carried out in air or in an inert atmosphere,depending upon the sensitivity of the materials.

In one embodiment, the radiation is selected from the group consistingof ultra-violet radiation (10-390 nm), visible radiation (390-770 nm),infrared radiation (770-10⁶ nm), and combinations thereof, includingsimultaneous and serial treatments. In one embodiment, the radiation isthermal radiation. In one embodiment, the exposure to radiation iscarried out by heating. The temperature and duration for the heatingstep is such that at least one physical property of the RSA is changed,without damaging any underlying layers of the light-emitting areas. Inone embodiment, the heating temperature is less than 250° C. In oneembodiment, the heating temperature is less than 150° C.

In one embodiment, the radiation is ultraviolet or visible radiation. Inone embodiment, the radiation is applied patternwise, resulting inexposed regions of RSA and unexposed regions of RSA.

In one embodiment, after patternwise exposure to radiation, the firstlayer is treated to remove either the exposed or unexposed regions ofthe RSA. Patternwise exposure to radiation and treatment to removeexposed or unexposed regions is well known in the art of photoresists.

In one embodiment, the exposure of the RSA to radiation results in achange in the solubility or dispersibility of the RSA in solvents. Whenthe exposure is carried out patternwise, this can be followed by a wetdevelopment treatment. The treatment usually involves washing with asolvent which dissolves, disperses or lifts off one type of area. In oneembodiment, the patternwise exposure to radiation results ininsolubilization of the exposed areas of the RSA, and treatment withsolvent results in removal of the unexposed areas of the RSA.

In one embodiment, the exposure of the RSA to visible or UV radiationresults in a reaction which decreases the volatility of the RSA inexposed areas. When the exposure is carried out patternwise, this can befollowed by a thermal development treatment. The treatment involvesheating to a temperature above the volatilization or sublimationtemperature of the unexposed material and below the temperature at whichthe material is thermally reactive. For example, for a polymerizablemonomer, the material would be heated at a temperature above thesublimation temperature and below the thermal polymerizationtemperature. It will be understood that RSA materials which have atemperature of thermal reactivity that is close to or below thevolatilization temperature, may not be able to be developed in thismanner.

In one embodiment, the exposure of the RSA to radiation results in achange in the temperature at which the material melts, softens or flows.When the exposure is carried out patternwise, this can be followed by adry development treatment. A dry development treatment can includecontacting an outermost surface of the element with an absorbent surfaceto absorb or wick away the softer portions. This dry development can becarried out at an elevated temperature, so long as it does not furtheraffect the properties of the originally unexposed areas.

After treatment with the RSA, and exposure to radiation, the first layerhas a lower surface energy than prior to treatment. In the case wherepart of the RSA is removed after exposure to radiation, the areas of thefirst layer that are covered by the RSA will have a lower surface energythat the areas that are not covered by the RSA.

One way to determine the relative surface energies, is to compare thecontact angle of a given liquid on the first organic active layer beforeand after treatment with the RSA. As used herein, the term “contactangle” is intended to mean the angle φ shown in FIG. 1. For a droplet ofliquid medium, angle φ is defined by the intersection of the plane ofthe surface and a line from the outer edge of the droplet to thesurface. Furthermore, angle φ is measured after the droplet has reachedan equilibrium position on the surface after being applied, i.e. “staticcontact angle”. A variety of manufacturers make equipment capable ofmeasuring contact angles.

The second layer is then applied over the RSA-treated first layer. Thesecond layer can be applied by any deposition technique. In oneembodiment, the second layer is applied by a liquid depositiontechnique. In this case, a liquid composition comprises a secondmaterial dissolved or dispersed in a liquid medium, applied over theRSA-treated first layer, and dried to form the second layer. The liquidcomposition is chosen to have a surface energy that is greater than thesurface energy of the RSA-treated first layer, but approximately thesame as or less than the surface energy of the untreated first layer.Thus, the liquid composition will wet the untreated first layer, butwill be repelled from the RSA-treated areas. The liquid may spread ontothe RSA-treated area, but it will de-wet.

In one embodiment, the RSA is patterned and the second layer is appliedusing a continuous liquid deposition technique. In one embodiment, thesecond layer is applied using a discontinuous liquid depositiontechnique.

In one embodiment, the RSA is unpatterned and the second layer isapplied using a discontinuous liquid deposition technique.

In one embodiment, the first layer is applied over a liquid containmentstructure. It may be desired to use a structure that is inadequate forcomplete containment, but that still allows adjustment of thicknessuniformity of the printed layer. In this case it may be desirable tocontrol wetting onto the thickness-tuning structure, providing bothcontainment and uniformity. It is then desirable to be able to modulatethe contact angle of the emissive ink. Most surface treatments used forcontainment (e.g., CF4 plasma) do not provide this level of control.

In one embodiment, the first layer is applied over a so-called bankstructure. Bank structures are typically formed from photoresists,organic materials (e.g., polyimides), or inorganic materials (oxides,nitrides, and the like). Bank structures may be used for containing thefirst layer in its liquid form, preventing color mixing; and/or forimproving the thickness uniformity of the first layer as it is driedfrom its liquid form; and/or for protecting underlying features fromcontact by the liquid. Such underlying features can include conductivetraces, gaps between conductive traces, thin film transistors,electrodes, and the like. It is often desirable to form regions on thebank structures possessing different surface energies to achieve two ormore purposes (e.g., preventing color mixing and also improvingthickness uniformity). One approach is to provide a bank structure withmultiple layers, each layer having a different surface energy. A morecost effective way to achieve this modulation of surface energy is tocontrol surface energy via modulation of the radiation used to cure aRSA. This modulation of curing radiation can be in the form of energydosage (power*exposure time), or by exposing the RSA through a photomaskpattern that simulates a different surface energy (e.g., expose througha half-tone density mask).

In one embodiment of the process provided herein, the first and secondlayers are organic active layers. The first organic active layer isformed over a first electrode, the first organic active layer is treatedwith a reactive surface-active composition to reduce the surface energyof the layer, and the second organic active layer is formed over thetreated first organic active layer.

In one embodiment, the first organic active layer is formed by liquiddeposition of a liquid composition comprising the first organic activematerial and a liquid medium. The liquid composition is deposited overthe first electrode, and then dried to form a layer. In one embodiment,the first organic active layer is formed by a continuous liquiddeposition method. Such methods may result in higher yields and lowerequipment costs.

In one embodiment, the RSA treatment is subsequent to the formation ofthe first organic active layer. In one embodiment, the RSA is is appliedas a separate layer overlying, and in direct contact with, the firstorganic active layer. In one embodiment, the RSA is deposited from asecond liquid composition. The liquid deposition method can becontinuous or discontinuous, as described above. In one embodiment, theRSA liquid composition is deposited using a continuous liquid depositionmethod.

The thickness of the RSA layer can depend upon the ultimate end use ofthe material. In some embodiments, the RSA layer is at least 100 Å inthickness. In some embodiments, the RSA layer is in the range of100-3000 Å; in some embodiments 1000-2000 Å.

After the RSA treatment, the treated first organic active layer isexposed to radiation. The type of radiation used will depend upon thesensitivity of the RSA as discussed above. The exposure can be ablanket, overall exposure, or the exposure can be patternwise.

In one embodiment, the exposure of the RSA to radiation results in achange in solubility or dispersibility of the RSA in a liquid medium. Inone embodiment, the exposure is carried out patternwise. This can befollowed by treating the RSA with a liquid medium, to remove either theexposed or unexposed portions of the RSA. In one embodiment, the RSA isradiation-hardenable and the unexposed portions are removed by theliquid medium.

4. Organic Electronic Device

The process will be further described in terms of its application in anelectronic device, although it is not limited to such application.

FIG. 2 is an exemplary electronic device, an organic light-emittingdiode (OLED) display that includes at least two organic active layerspositioned between two electrical contact layers. The electronic device100 includes one or more layers 120 and 130 to facilitate the injectionof holes from the anode layer 110 into the photoactive layer 140. Ingeneral, when two layers are present, the layer 120 adjacent the anodeis called the hole injection layer or buffer layer. The layer 130adjacent to the photoactive layer is called the hole transport layer. Anoptional electron transport layer 150 is located between the photoactivelayer 140 and a cathode layer 160. Depending on the application of thedevice 100, the photoactive layer 140 can be a light-emitting layer thatis activated by an applied voltage (such as in a light-emitting diode orlight-emitting electrochemical cell), a layer of material that respondsto radiant energy and generates a signal with or without an applied biasvoltage (such as in a photodetector). The device is not limited withrespect to system, driving method, and utility mode.

For multicolor devices, the photoactive layer 140 is made up differentareas of at least three different colors. The areas of different colorcan be formed by printing the separate colored areas. Alternatively, itcan be accomplished by forming an overall layer and doping differentareas of the layer with emissive materials with different colors. Such aprocess has been described in, for example, published U.S. patentapplication 2004-0094768.

In one embodiment, the new process described herein can be used to applyan organic layer (second layer) to an electrode layer (first layer). Inone embodiment, the first layer is the anode 110, and the second layeris the buffer layer 120.

In some embodiments, the new process described herein can be used forany successive pairs of organic layers in the device, where the secondlayer is to be contained in a specific area. In one embodiment of thenew process, the second organic active layer is the photoactive layer140, and the first organic active layer is the device layer applied justbefore layer 140. In many cases the device is constructed beginning withthe anode layer. When the hole transport layer 130 is present, the RSAtreatment would be applied to layer 130 prior to applying thephotoactive layer 140. When layer 130 was not present, the RSA treatmentwould be applied to layer 120. In the case where the device wasconstructed beginning with the cathode, the RSA treatment would beapplied to the electron transport layer 150 prior to applying thephotoactive layer 140.

In one embodiment of the new process, the second organic active layer isthe hole transport layer 130, and the first organic active layer is thedevice layer applied just before layer 130. In the embodiment where thedevice is constructed beginning with the anode layer, the RSA treatmentwould be applied to buffer layer 120 prior to applying the holetransport layer 130.

In one embodiment, the anode 110 is formed in a pattern of parallelstripes. The buffer layer 120 and, optionally, the hole transport layer130 are formed as continuous layers over the anode 110. The RSA isapplied as a separate layer directly over layer 130 (when present) orlayer 120 (when layer 130 is not present). The RSA is exposed in apattern such that the areas between the anode stripes and the outeredges of the anode stripes are exposed.

The layers in the device can be made of any materials which are known tobe useful in such layers. The device may include a support or substrate(not shown) that can be adjacent to the anode layer 110 or the cathodelayer 150. Most frequently, the support is adjacent the anode layer 110.The support can be flexible or rigid, organic or inorganic. Generally,glass or flexible organic films are used as a support. The anode layer110 is an electrode that is more efficient for injecting holes comparedto the cathode layer 160. The anode can include materials containing ametal, mixed metal, alloy, metal oxide or mixed oxide. Suitablematerials include the mixed oxides of the Group 2 elements (i.e., Be,Mg, Ca, Sr, Ba, Ra), the Group 11 elements, the elements in Groups 4, 5,and 6, and the Group 8-10 transition elements. If the anode layer 110 isto be light transmitting, mixed oxides of Groups 12, 13 and 14 elements,such as indium-tin-oxide, may be used. As used herein, the phrase “mixedoxide” refers to oxides having two or more different cations selectedfrom the Group 2 elements or the Groups 12, 13, or 14 elements. Somenon-limiting, specific examples of materials for anode layer 110include, but are not limited to, indium-tin-oxide (“ITO”),aluminum-tin-oxide, gold, silver, copper, and nickel. The anode may alsocomprise an organic material such as polyaniline, polythiophene, orpolypyrrole.

The anode layer 110 may be formed by a chemical or physical vapordeposition process or spin-cast process. Chemical vapor deposition maybe performed as a plasma-enhanced chemical vapor deposition (“PECVD”) ormetal organic chemical vapor deposition (“MOCVD”). Physical vapordeposition can include all forms of sputtering, including ion beamsputtering, as well as e-beam evaporation and resistance evaporation.Specific forms of physical vapor deposition include rf magnetronsputtering and inductively-coupled plasma physical vapor deposition(“IMP-PVD”). These deposition techniques are well known within thesemiconductor fabrication arts.

Usually, the anode layer 110 is patterned during a lithographicoperation. The pattern may vary as desired. The layers can be formed ina pattern by, for example, positioning a patterned mask or resist on thefirst flexible composite barrier structure prior to applying the firstelectrical contact layer material. Alternatively, the layers can beapplied as an overall layer (also called blanket deposit) andsubsequently patterned using, for example, a patterned resist layer andwet chemical or dry etching techniques. Other processes for patterningthat are well known in the art can also be used. When the electronicdevices are located within an array, the anode layer 110 typically isformed into substantially parallel strips having lengths that extend insubstantially the same direction.

The buffer layer 120 functions to facilitate injection of holes into thephotoactive layer and to smoothen the anode surface to prevent shorts inthe device. The buffer layer is typically formed with polymericmaterials, such as polyaniline (PANI) or polyethylenedioxythiophene(PEDOT), which are often doped with protonic acids. The protonic acidscan be, for example, poly(styrenesulfonic acid),poly(2-acrylamido-2-methyl-1-propanesulfonic acid), and the like. Thebuffer layer 120 can comprise charge transfer compounds, and the like,such as copper phthalocyanine and thetetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ). In oneembodiment, the buffer layer 120 is made from a dispersion of aconducting polymer and a colloid-forming polymeric acid. Such materialshave been described in, for example, published U.S. patent applications2004-0102577 and 2004-0127637.

The buffer layer 120 can be applied by any deposition technique. In oneembodiment, the buffer layer is applied by a solution deposition method,as described above. In one embodiment, the buffer layer is applied by acontinuous solution deposition method.

Examples of hole transport materials for optional layer 130 have beensummarized for example, in Kirk-Othmer Encyclopedia of ChemicalTechnology, Fourth Edition, Vol. 18, p. 837-860, 1996, by Y. Wang. Bothhole transporting molecules and polymers can be used. Commonly used holetransporting molecules include, but are not limited to:4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine (TDATA);4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine (MTDATA);N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD); 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane (TAPC);N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD); tetrakis-(3-methylphenyl)-N,N, N′,N′-2,5-phenylenediamine (PDA);α-phenyl-4-N,N-diphenylaminostyrene (TPS); p-(diethylamino)benzaldehydediphenylhydrazone (DEH); triphenylamine (TPA);bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP);1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline (PPR or DEASP); 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane(DCZB); N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine(TTB); N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB); andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers include, but are not limited to,polyvinylcarbazole, (phenylmethyl)polysilane, poly(dioxythiophenes),polyanilines, and polypyrroles. It is also possible to obtain holetransporting polymers by doping hole transporting molecules such asthose mentioned above into polymers such as polystyrene andpolycarbonate. In some embodiments, the hole transport materialcomprises a cross-linkable oligomeric or polymeric material. After theformation of the hole transport layer, the material is treated withradiation to effect cross-linking. In some embodiments, the radiation isthermal radiation.

The hole transport layer 130 can be applied by any deposition technique.In one embodiment, the hole transport layer is applied by a solutiondeposition method, as described above. In one embodiment, the holetransport layer is applied by a continuous solution deposition method.

Any organic electroluminescent (“EL”) material can be used in thephotoactive layer 140, including, but not limited to, small moleculeorganic fluorescent compounds, fluorescent and phosphorescent metalcomplexes, conjugated polymers, and mixtures thereof. Examples offluorescent compounds include, but are not limited to, pyrene, perylene,rubrene, coumarin, derivatives thereof, and mixtures thereof. Examplesof metal complexes include, but are not limited to, metal chelatedoxinoid compounds, such as tris(8-hydroxyquinolato)aluminum (Alq3);cyclometalated iridium and platinum electroluminescent compounds, suchas complexes of iridium with phenylpyridine, phenylquinoline, orphenylpyrimidine ligands as disclosed in Petrov et al., U.S. Pat. No.6,670,645 and Published PCT Applications WO 03/063555 and WO2004/016710, and organometallic complexes described in, for example,Published PCT Applications WO 03/008424, WO 03/091688, and WO 03/040257,and mixtures thereof. Electroluminescent emissive layers comprising acharge carrying host material and a metal complex have been described byThompson et al., in U.S. Pat. No. 6,303,238, and by Burrows and Thompsonin published PCT applications WO 00/70655 and WO 01/41512. Examples ofconjugated polymers include, but are not limited topoly(phenylenevinylenes), polyfluorenes, poly(spirobifluorenes),polythiophenes, poly(p-phenylenes), copolymers thereof, and mixturesthereof.

The photoactive layer 140 can be applied by any deposition technique. Inone embodiment, the photoactive layer is applied by a solutiondeposition method, as described above. In one embodiment, thephotoactive layer is applied by a continuous solution deposition method.

Optional layer 150 can function both to facilitate electroninjection/transport, and can also serve as a confinement layer toprevent quenching reactions at layer interfaces. More specifically,layer 150 may promote electron mobility and reduce the likelihood of aquenching reaction if layers 140 and 160 would otherwise be in directcontact. Examples of materials for optional layer 150 include, but arenot limited to, metal-chelated oxinoid compounds (e.g., Alq₃ or thelike); phenanthroline-based compounds (e.g.,2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (“DDPA”),4,7-diphenyl-1,10-phenanthroline (“DPA”), or the like); azole compounds(e.g., 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (“PBD” orthe like), 3-(4-biphenylyl)4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole(“TAZ” or the like); other similar compounds; or any one or morecombinations thereof. Alternatively, optional layer 150 may be inorganicand comprise BaO, LiF, Li₂O, or the like.

The cathode 160, is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode layer 160can be any metal or nonmetal having a lower work function than the firstelectrical contact layer (in this case, the anode layer 110). In oneembodiment, the term “lower work function” is intended to mean amaterial having a work function no greater than about 4.4 eV. In oneembodiment, “higher work function” is intended to mean a material havinga work function of at least approximately 4.4 eV.

Materials for the cathode layer can be selected from alkali metals ofGroup 1 (e.g., Li, Na, K, Rb, Cs,), the Group 2 metals (e.g., Mg, Ca,Ba, or the like), the Group 12 metals, the lanthanides (e.g., Ce, Sm,Eu, or the like), and the actinides (e.g., Th, U, or the like).Materials such as aluminum, indium, yttrium, and combinations thereof,may also be used. Specific non-limiting examples of materials for thecathode layer 160 include, but are not limited to, barium, lithium,cerium, cesium, europium, rubidium, yttrium, magnesium, samarium, andalloys and combinations thereof.

The cathode layer 160 is usually formed by a chemical or physical vapordeposition process.

In other embodiments, additional layer(s) may be present within organicelectronic devices.

When the device is made starting with the anode side, the RSA treatmentstep of the new process described herein may be after the formation ofthe anode 110, after the formation of the buffer layer 120, after thehole transport layer 130, or any combination thereof. When the device ismade starting with the cathode side, the RSA treatment step of the newprocess described herein, may be after the formation of the cathode 160,the electron transport layer 150, or any combination thereof.

The different layers may have any suitable thickness. Inorganic anodelayer 110 is usually no greater than approximately 500 nm, for example,approximately 10-200 nm; buffer layer 120, and hole transport layer 130are each usually no greater than approximately 250 nm, for example,approximately 50-200 nm; photoactive layer 140, is usually no greaterthan approximately 1000 nm, for example, approximately 50-80 nm;optional layer 150 is usually no greater than approximately 100 nm, forexample, approximately 20-80 nm; and cathode layer 160 is usually nogreater than approximately 100 nm, for example, approximately 1-50 nm.If the anode layer 110 or the cathode layer 160 needs to transmit atleast some light, the thickness of such layer may not exceedapproximately 100 nm.

EXAMPLES

The concepts described herein will be further described in the followingexamples, which do not limit the scope of the invention described in theclaims.

Example 1

Example 1 demonstrates an RSA treatment that is coincidental with theformation of the first layer. The first layer is an organic activelayer.

Coating 1: A first organic active layer of Material A (a cross-linkablehole transport material from Sumitomo Chemical Col, Tokyo, Japan) wasspin-coated from p-xylene onto a glass slide.

Coating 2: A first organic active layer was made from a solutioncontaining 95% Material A and 5% of a fluorinated unsaturated estermonomer as an RSA (Zonyl® 8857A, from E. I. du Pont de Nemours andCompany, Wilmington, Del.) by spin-coating onto a glass slide.

Both coatings were dried at 130 C on a hot plate in air. Spin coatingconditions were adjusted to provide films with similar thickness afterdrying. The coated materials were thermally cured in a convection ovenwith a nitrogen atmosphere at 200° C. for 30 minutes. An emissive inkmade of BD052 and BH140 (Idemitsu Kosan Ltd., Chiba, Japan) in a ratioof 8:92, at 1.5% total solids, in anisole, was printed onto each of thecoatings using a MicroFab printer, with a stage temperature of 50° C.Spreading of the ink on the two surfaces was compared by measuring thediameter of the printed drops after drying. The ink spread 7% less oncoating 2 containing the RSA vs. coating 1 devoid of RSA. The contactangle of anisole was about 9 degrees on coating 1, and about 15 degreeson the surface of coating 2 containing Zonyl® 8857A.

Example 2

Example 2 demonstrates an RSA treatment that is subsequent to theformation of the first layer. The first layer is an organic activelayer.

Coatings of Material A were prepared on glass slides and cured at 200°C. for 30 minutes in a convection oven with a nitrogen atmosphere. Asolution of a fluorinated acrylate monomer as an RSA (Zonyl® TA-N, fromE. I. du Pont de Nemours and Company, Wilmington, Del.) was spin-coatedonto the cured Material A surface. The RSA solution was about 20% solidsin hexafluoropropoxybenzene. The RSA was cured by heating at 130° C. ona hot plate in air. Any uncured RSA was rinsed off by soaking intrifluorotoluene in a petri dish for 15 minutes, and dried at ambienttemperature in air. The contact angle of the cured, uncoated Material Awas measured as about 9 degrees using anisole. The contact angle of thecured, uncoated Material A was identical within experimental error ifthe surface was simply rinsed with trifluorotoluene (no RSA coating).The contact angle was identical within experimental error if the RSA wascoated onto the Material A and washed off with trifluorotoluene withoutreacting the RSA in the oven. The contact angle of the oven-cured RSAsurface was 27 degrees. This demonstrates that the RSA can be appliedand removed without affecting the underlying surface energy, and thedifference vs. the cured film can be readily measured.

Example 3

Example 3 demonstrates an RSA treatment that is subsequent to theformation of the first layer. The first layer is an organic activelayer.

Glass slides were coated with Material A and thermally cured asdescribed above. On some slides the Material A was overcoated with asolution of RSA (Zonyl® TA-N) as described above, and the RSA was driedat ambient. The thickness of the RSA coating was determined to be about100 Angstrom (A) using a VEECO NT3300 inteferometric profilometer. TheRSA was exposed to actinic radiation (365-405 nm, 2.7 Joule/cm̂2) in air;half this glass slide was masked off to prevent exposure. After exposurethe uncured RSA was washed off by soaking in trifluorotoluene for 3minutes. The contact angle of anisole on the region where the RSA hadbeen exposed to actinic radiation was 40 degrees. The contact angle inthe unexposed region was identical to Material A within experimentalerror, showing the unexposed RSA was completely soluble and could berinsed cleanly from the Material A surface. A coating of Material Awithout RSA was exposed to actinic radiation and the contact angle wasunchanged. This demonstrates creating a pattern in the RSA by exposureto actinic radiation, and the change in surface energy is due to the RSAand not to the processing steps.

Example 4

Example 4 demonstrates an RSA treatment that is subsequent to theformation of the first layer. This example also demonstrates containmentas it would be practiced during printing of an emissive ink. The exampleis shown in FIGS. 3 through 6.

A glass substrate, shown as 200 in FIG. 3, with a coating of indium tinoxide (ITO) about 1100 Å thick, was patterned photolithographically tocreate an array of lines of ITO, shown as 210, with widths of about 90microns, and spacing of 10 microns between the lines. A layer 220 ofMaterial A was coated over the array of lines and cured at 200° C. in aconvection oven with an nitrogen atmosphere for 30 minutes, as shown inFIG. 4. The Material A-coated ITO lines are shown as 211. A coating 230of Zonyl® TA-N was applied over the Material A on one substrate by spincoating from hexafluoropropoxybenzene, and dried in air, as shown inFIG. 5. This coating was exposed to radiation from a source with themajority of its emission in the range of 365-404 nm using a negativephotomask so the exposed regions covered the gaps between the ITO lines,and 2-3 microns of the edge of the ITO line. The exposure was about 3.8J/cm̂2. The plates were washed in trifluorotoluene to remove theunexposed RSA. FIG. 6 shows the piece after development, withRSA-covered areas 230 and Material A-covered areas over the ITO, 211 andMaterial A-covered areas over the glass, 220. An emissive ink comprisingBH119 and BH215 (both from Idemitsu) in a ratio of 8:92, at 1.5% totalsolids, in anisole, was printed onto the ITO lines using a MicroFabprinter, at ambient. The drop volume was about 40-45 picoliters, and thedrop spacing was 0.08 mm, creating continuous lines of printing. On thepanel without the RSA the printed lines spread about 200-300 microns;that is, the ink spread across 3 ITO lines. This would have resulted inunacceptable color mixing in an actual printing process. On the panelwith the patterned RSA the ink was contained entirely within the regiontreated with the RSA, and would have resulted in a high quality printeddevice.

Example 5

Example 5 demonstrates an RSA treatment that is subsequent to theformation of the first layer.

Coatings of Material A were prepared and thermally cured as describedabove. These were then overcoated with RSA coatings of Zonyl® TA-N asdescribed above. The RSA coatings received blanket exposures up to about4 J/cm̂2. The coatings were washed in trifluorotoluene after exposure,and contact angles were measured with anisole. The anisole contact anglewas modulated from about 9 degrees (Material A surface) to 40-45degrees. No significant difference was observed if the exposures wereperformed in air or an inert atmosphere.

Example 6

Example 6 demonstrates an RSA treatment that is subsequent to theformation of the first layer, where removal of unexposed region isaccomplished via sublimation.

Coatings of Material A were prepared and thermally cured as describedabove. These were then overcoated with RSA coatings ofheneicosafluorododecylacrylate by spin coating from a 3% wt/vol solutionin perfluorooctance. One of the RSA coatings received a blanket UVexposure of about 1.5 J/cm²; the other coating did not receive a UVexposure. The two coatings were baked at 195° C. for 20 minutes on a hotplate in air, and contact angles were measured with anisole. The anisolecontact angle was about 55 degrees on the RSA coating that had beenexposed to UV radiation. The anisole contact angle was 10 degrees on thecoating that had not been exposed to UV radiation. This demonstratesthat the RSA that has not been exposed to UV radiation can be removed byheating. If the RSA coating had been exposed to UV radiation in apattern, and then heated, the RSA would have remained in the exposedareas with a contact angle of about 55 degrees, and the unexposed areaswould have had a contact angle of about 10 degrees.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed.

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofinvention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

It is to be appreciated that certain features are, for clarity,described herein in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.Further, reference to values stated in ranges include each and everyvalue within that range.

1. A process for forming a contained second layer over a first layer,said process comprising: forming the first layer having a first surfaceenergy; treating the first layer with a reactive surface-activecomposition to form a treated first layer having a second surface energywhich is lower than the first surface energy; exposing the treated firstlayer with radiation; and forming the second layer.
 2. The process ofclaim 1, wherein the reactive surface-active composition is afluorinated material.
 3. The process of claim 1, wherein the reactivesurface-active composition is a radiation-hardenable material.
 4. Theprocess of claim 1, wherein the reactive surface-active composition is acrosslinkable fluorinated surfactant.
 5. The process of claim 1, whereinthe reactive surface-active composition is deposited with the firstlayer.
 6. The process of claim 1, wherein the reactive surface-activecomposition is applied as a separate layer over the first layer.
 7. Theprocess of claim 1, wherein the radiation is applied in a pattern toform exposed regions and unexposed region of the reactive surface-activecomposition.
 8. The process of claim 7, further comprising removingeither the exposed or unexposed regions of the reactive surface-activecomposition.
 9. The process of claim 8, wherein the regions are removedby treating with a liquid.
 10. The process of claim 8, wherein theregions are removed by heating.
 11. The process of claim 8, wherein theregions are removed by contacting an outermost surface of the with anabsorbent surface to absorb or wick away the softer regions.
 12. Aprocess for making an organic electronic device comprising a firstorganic active layer and a second organic active layer positioned overan electrode, said process comprising forming the first organic activelayer having a first surface energy over the electrode treating thefirst organic active layer with a reactive surface-active composition toform a treated first organic active layer, exposing the treated firstorganic active layer with radiation, thereby reducing the first surfaceenergy, and forming the second organic active layer.
 13. An organicelectronic device comprising a first organic active layer and a secondorganic active layer positioned over an electrode, and furthercomprising a reactive surface-active composition between the firstorganic active layer and the second organic active layer.